1. Field of the Invention
The invention relates to an applicator shoe for applying labels. More particularly, the invention relates to an applicator shoe that pivots so as to engage and disengage the label recipient during the labeling process.
2. Description of Related Art
The use of separate labels applied to various products is well known. In particular, adhesive-backed labels are often applied to cards, i.e. identification cards, credit cards, transaction cards, etc. Since such cards may be produced in large numbers, it is useful to utilize a tool to apply the labels rather than applying them by hand. In particular, an automated labeling mechanism may be used to apply labels to cards or other products.
Conventionally, adhesive labels often are disposed on a liner, both for convenience of handling and to protect the adhesive from contamination or degradation until the label is applied to the card or other label recipient. The label adheres only weakly to the liner, so that it may be removed conveniently when it is to be applied.
For labels arranged in such a fashion, labeling mechanisms may include an affixer shoe. Conventionally, an affixer shoe is a flat, relatively thin plate or sheet of material, such as sheet steel. When the liner with the label thereon is moved around the shoe, it is required to make a sharp turn as it passes the edge of the shoe. The label tends to separate from the liner at the edge of the shoe, rather than making the turn. Consequently, the adhesive backing of the label is gradually exposed as the liner advances past the edge of the shoe. If the recipient of the label is disposed near the shoe in a position to receive the label, the label may be conveniently transferred from the liner to the label recipient.
For purposes of removing the label and applying it to the label recipient, relative motion between the liner and the shoe edge is required. However, this may be accomplished either by moving the shoe, by moving the liner with the label thereon, or by some combination of the two. In many conventional devices, the shoe is moved instead of the liner and label, however, the effect is the same.
Regardless of which component or components move, in such a manner a label may be readily removed from a liner and applied to a card or other product. When it is desired to place a large number of labels, a long strip or roll of liner with many labels disposed thereon is conventionally used. Cards or other label recipients are fed sequentially into the label receiving position, and the shoe is moved to separate a label from the liner and apply it to each recipient.
When a label is applied, the edge of the shoe should be close to or in contact with the label recipient, so that the label may adhere in the proper position on the recipient as it separates from the liner. However, if the shoe is too close to the label recipient as the recipient is fed to or from the label receiving position, a variety of mishaps may occur, i.e. the apparatus may jam, the label recipient may be damaged, the shoe may be damaged or misaligned, the label may be placed in the wrong position on the recipient or may not be applied properly or at all, etc.
Therefore, it is conventional to translate the shoe between first and second positions. In the first position the shoe is well clear of the label receiving position so that the label recipient may be fed thereto or therefrom. In the second position the shoe is arranged with the edge near to or in contact with the label recipient. The shoe is disposed in the first position except when labels actually are being applied, during which time the shoe is in the second position.
However, this arrangement has several limitations.
For example, the second position wherein the shoe is clear of the label recipient normally is a considerable distance from the first position wherein the shoe is proximate the label recipient. Consequently, a relatively large translation is necessary on each stroke between the first and second positions, so as to keep the shoe clear of the transport path for the label recipient when the recipient is moved in and out of the label receiving position.
A schematic illustration of this difficulty is shown in FIG. 1. In FIG. 1A, a conventional label module 10 includes a shoe 12. As may be seen, the conventional shoe 12 is merely a flat sheet of material, as might be made by punching or cutting a blank of sheet metal. Guide rollers 14 and 16 help guide a liner 18 with labels thereon (not shown). As shown, the shoe 12 is arranged well above the card 20 so as not to interfere with the feeding of the card 20 into or out of the module 10. Thus, in FIG. 1A the shoe 12 is in the first position.
FIG. 1B shows the same conventional label module 10 with the shoe 12 in the second position, ready to apply a label to the card 20.
As may be seen, the stroke that the conventional shoe 12 must follow between its first and second positions is relatively long, at least on the order of the height of the card and possibly much longer. For example, although for clarity FIG. 1 shows only the shoe 12 and the guide rollers 14 and 16, the module 10 may include various other components as well, i.e. gear trains, actuators, etc. Some of these components may move with the shoe 12, and they must also be translated well clear of the card 20. Likewise, whatever mechanism is used to feed the card 20 may include components that extend past the card 20 itself in one or more directions, and it may also be necessary for the shoe 12 to translate clear of those components.
The time required to translate the shoe over such a long stroke necessarily limits the speed of operation, i.e. in number of labels applied per hour, of a conventional labeling apparatus.
Furthermore, because the stroke is long, an apparatus suited for even moderate speeds may require relatively high-performance components, i.e. high-speed motors, etc. Such high-performance components may be expensive, difficult to manufacture, etc., and so may increase the cost and/or complexity of the system.
In addition, as may be noted from a comparison of FIGS. 1A and 1B, the amount of liner 18 that is disposed between the guide rollers 14 and 16 is much less in the first position than in the second position. In order to keep loose gathers of liner 18 from interfering with feeding the card 20 or other operations, the liner 18 must be retracted and retained under tension.
If the liner 18 is not retracted from both sides, i.e. in the direction of both roller 14 and roller 16, the position of the liner 18 with respect to the edge 22 of the shoe 12 will change. In that case, the position of the next label on the liner 18 with respect to the edge 22 will also change. This may reduce the accuracy of label placement. For this reason, the liner 18 must be retracted with relatively high precision on both sides of the shoe 12. Thus, for a conventional label module 10 one or more precisely controllable reversible motors are required on both the supply side and the take-up side of the shoe 12.
The need to use such high precision reversible motors and the drive trains, controllers, etc. necessary to support them may increase the cost and/or complexity of a conventional label module 10.
Furthermore, even with high precision motors, the relatively large translation that the shoe 12 must make may introduce a greater potential for errors in positioning the liner 18 with respect to the edge 22 and/or the card 20. This is turn may lead to inaccuracies in label placement. Also, even if arrangements are made to compensate for such inaccuracies, those arrangements may further increase the cost and complexity of a conventional label module 10. Likewise, such arrangements may further reduce the speed of a conventional label module 10, since adjustment of the liner 18 to compensate for positioning errors may require time.